Computers use a variety of systems to "write" or store programs and data. Examples of systems include electromagnetism and lazer-written processes such as flop-optics. The write/read head in the computer drive converts electric code signals from the computer into magnetic codes recorded on the surface of the disk. The disk drive then reverses this process to "read" the disk. A general discussion of this process may be found in Macaulay, D., 1988, The Way Things Work, Houghton-Mifflin Company, Boston, pp. 302-303 and 340.
A floppy disk is a flexible magnetic disk used in a disk drive of a computer to store or retrieve programs and data. The disk is inserted into the disk drive of the computer by hand. The disk is protected by a jacket in which a window is cut to expose the surface of the disk. Inside the disk drive, the head travels along the window as the disk rotates inside the jacket. The jacket also prevents the disk from damage during the handling process.
There are two common types of floppy disks in the computer industry: a 31/2 inch size disk and a 51/4 inch disk. The present invention is specifically directed to the 31/2 inch size disk, illustrated in FIGS. 1-3 and described later in this disclosure, primarily because it incorporates a write-protect system comprising a small window extending through the disk jacket. The write-protect system is intended to prevent inadvertent erasure of the information recorded on the disk. By obstructing the window with a write-protect button, also described later in this disclosure, the disk operates in the "write/read" format. When the window is not blocked, the disk only serves in the "read only" format.
The 51/4 inch disk has a similar write/read capability; however, the write/read assembly in the 51/4 inch disk usually includes a notch formed on the edge of the disk. In order to change the "read only" format of the 51/4 inch disk into a "write/read" format, the notch must be filled in. Disclosures such as U.S. Pat. No. 4,649,452 to Brugman, U.S. Pat. No. 4,658,317 to Lievsay, Jr., U.S. Pat. No. 4,771,354 to Zschau, U.S. Pat. No. 4,757,407 to Simokat, U.S. Pat. No. 4,969,060 to O'Neill, and U.S. Pat. No. 4,618,060 to Tarter all illustrate various forms of write-protect clips designed to be retrofitted onto a 5-inch floppy disk to turn the disk into a "read only" disk.
Reference is made to U.S. Pat. No. 4,409,630 to Saito, which discloses a write-protect tab assembly including a write-protect button slidably mounted in a pocket formed in the jacket of a computer disk. U.S. Pat. No. Re. 33,961 to Swinburne et al. is also directed to a write-protect tab assembly for a floppy disk jacket. Unlike Saito, the Swinburne et al. tab is designed to snap onto or be "encaptured" by a jacket base before the cover of the jacket enclosing the floppy disk is attached to the base. Apparently, the cover must sometimes be removed from the base after the jacket has been assembled and sealed. In the Saito disclosure, the write-protect button is not "encaptured" in the floppy disk jacket. When the jacket assembly is subsequently disassembled, the button falls out during the handling process. Swinburne et al. resolve this problem by slidably attaching the button to the base so that it will not fall out. However, the tab is not designed to be retrofitted into an assembled floppy disk jacket.
Computer floppy disks are commonly prepared with a write-protect assembly, as disclosed in the '630 patent to Saito and the '961 patent to Swinburne et al. The assembly gives the computer disk owner the option of using the disk in the "write/read" mode, in which the computer operator can read, enter and delete information from the disk or the "read only" mode, in which the operator can read information from the disk but not insert or delete information. This capability is accomplished by a slidable button, which will be described further on in this disclosure.
Many of the disks currently being produced for consumer use, especially the pre-programmed disks, i.e., disks containing previously entered software for use by a computer operator in the operator's computer, do not contain the slidable write-protect button in the floppy disk jacket. Thus, the "read only" window cannot be blocked which leaves the disk in the "read only" format. Unless the window can be obscured somehow, the disk is suitable only for reading the information previously placed on the floppy disk. This makes the floppy disk unfit for further use after the information has been transferred onto a computer disk hard drive. Presently, there is no means to retrofit a floppy disk with a write-protect button.